Tools: Testbench: Add README.md text

This text add helps with various usages for testbench.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

tools/testbench/README.md

@@ -0,0 +1,154 @@
+# SOF testbench
+
+### Features
+
+ * Simulate IPC3 and IPC4 SOF versions with run of set of processing
+   components based on desired topology.
+ * Replaces host and dai components with file I/O with raw binary
+   S16_LE/S24_LE/S32_LE or text format files for audio waveforms.
+ * Much faster than real-time execution in native build, e.g. x86 on
+   Linux for efficient validation usage.
+ * With xtensa DSP build offers cycles accurate simulated environment
+   execution. And also with options for similation speed vs. model
+   accuracy.
+ * Allows easy use of conventional debugger, profiler, leak and memory check
+   tools usage for DSP firmware code.
+
+### Quick how-to
+
+The simplest way to build and execute testbench is with supplied
+scripts. It executes a simple chirp waveform test for a number of
+processing components.  Corrupted audio or failure in execution
+results to fail of test.
+
+The commands "build-tools.sh -t" and "host-testbench.sh" are currently
+valid only for default IPC3 build of testbench.
+
+```
+cd $SOF_WORKSPACE/sof
+scripts/build-tools.sh -t
+scripts/rebuild-testbench.sh
+scripts/host-testbench.sh
+```
+
+### Manual run of IPC3 testbench
+
+As an example, process a wav file and listen it. The example
+proceccing component is DC block. The wav file is first converted with
+sox to raw 32 bit 48 kHz stereo format, then processed by testbench,
+converted back to wav.
+
+```
+cd $SOF_WORKSPACE/sof
+sox --encoding signed-integer /usr/share/sounds/alsa/Front_Left.wav -L -r 48000 -c 2 -b 32 in.raw
+tools/testbench/build_testbench/install/bin/testbench -r 48000 -R 48000 -c 2 -n 2 -b S32_LE \
+   -t tools/build_tools/test/topology/test-playback-ssp5-mclk-0-I2S-dcblock-s32le-s32le-48k-24576k-codec.tplg \
+   -i in.raw -o out.raw
+sox --encoding signed-integer -L -r 48000 -c 2 -b 32 in.raw out.wav
+aplay out.wav
+```
+
+The testbench binary can be debugged and profiled with native
+executable tools like gdb, ddd (GUI for gdb), gprof, and valgrind.
+
+### Profiling of testbench run on xtensa
+
+Fist, the testbench is build in this example for Intel MTL
+platform. This needs access to Cadence Xplorer toolchain with the core
+confiration for the platform.
+
+```
+cd $SOF_WORKSPACE/sof
+export XTENSA_TOOLS_ROOT=~/xtensa/XtDevTools
+export ZEPHYR_TOOLCHAIN_VARIANT=xt-clang
+scripts/rebuild-testbench.sh -p mtl
+source tools/testbench/build_xt_testbench/xtrun_env.sh
+```
+
+Next the testbench is run with xt-run simulator. The example component
+is dynamic range processing (DRC). For proling data generate use
+option --profile. Note that this is a lot slower than native run. An
+1s extract of a pink noise file is used as example.
+
+```
+sox --encoding signed-integer /usr/share/sounds/alsa/Noise.wav -L -r 48000 -c 2 -b 32 in.raw trim 0.0 1.0
+$XTENSA_PATH/xt-run --profile=profile.out tools/testbench/build_xt_testbench/testbench \
+   -q -r 48000 -R 48000 -c 2 -n 2 -b S32_LE \
+   -t tools/build_tools/test/topology/test-playback-ssp5-mclk-0-I2S-drc-s32le-s32le-48k-24576k-codec.tplg \
+   -i in.raw -o out.raw 2> trace.txt
+```
+
+Then convert the profiler data to readable format and check it.
+
+Note: Current version of testbench does not have functional quiet mode
+"-q" switch to suppress trace. Due all debug traces print
+out. Majority of performance is spent in printing.
+
+```
+$XTENSA_PATH/xt-gprof tools/testbench/build_xt_testbench/testbench profile.out > example_profile.txt
+less example_profile.txt
+```
+
+### Perform audio processing quality checks
+
+This step needs Matlab or Octave tool with signal processing
+package. A number of tests is performed for IIR equalizer component as
+example. The script opens plot windows and outputs a text report in
+the end. A simple pass/fail criteria is used to report a verdict of
+the test run.
+
+```
+cd $SOF_WORKSPACE/sof/tools/test/audio
+octave -q --eval "pkg load signal io; [n_fail]=process_test('eq-iir', 32, 32, 48000, 1, 1); input('Press ENTER'); exit(n_fail)"
+```
+
+See from interactive Octave shell command "help process_test" the
+explanation for the test run parameters.
+
+### Manual run of IPC4 testbench
+
+Apply this patch to SOF and rebuild it.
+
+```
+diff --git a/src/arch/host/configs/library_defconfig b/src/arch/host/configs/library_defconfig
+index d150690aa..6d167dfba 100644
+--- a/src/arch/host/configs/library_defconfig
++++ b/src/arch/host/configs/library_defconfig
+@@ -21,8 +21,8 @@ CONFIG_COMP_VOLUME=y
+ CONFIG_COMP_VOLUME_LINEAR_RAMP=y
+ CONFIG_COMP_VOLUME_WINDOWS_FADE=y
+ CONFIG_DEBUG_MEMORY_USAGE_SCAN=n
+-CONFIG_IPC_MAJOR_3=y
+-CONFIG_IPC_MAJOR_4=n
++CONFIG_IPC_MAJOR_3=n
++CONFIG_IPC_MAJOR_4=y
+ CONFIG_LIBRARY=y
+ CONFIG_LIBRARY_STATIC=y
+ CONFIG_MATH_IIR_DF2T=y
+```
+
+Then process a wav file and listen. The example proceccing component
+is DC blocker. The wav file is first converted with sox to raw 32 bit
+48 kHz stereo format, then processed by testbench, converted back to
+wav.
+
+```
+cd $SOF_WORKSPACE/sof
+sox --encoding signed-integer /usr/share/sounds/alsa/Front_Center.wav -L -r 48000 -c 2 -b 32 in.raw
+tools/testbench/build_testbench/install/bin/testbench -r 48000 -R 48000 -c 2 -n 2 -b S32_LE -p 1,2 \
+   -t tools/build_tools/topology/topology2/development/sof-hda-benchmark-dcblock32.tplg \
+   -i in.raw -o out.raw
+sox --encoding signed-integer -L -r 48000 -c 2 -b 32 in.raw out.wav
+aplay out.wav
+```
+
+The difference in command line is the use of other topology for IPC4
+and use of -p command line option to select pipelines 1 and 2 from
+this topology for scheduling and connecting to input and output files.
+In this topology the host playback pipeline is 1 and the dai playback
+side pipeline is 2. Capture side pipelines would be 3 and 4. And
+running both playback and capture would need more input and output
+files to be added to -i and -o as comma separated. The more advanced
+use cases simulations with IPC4 are still under work.
+
+The debugging and profiling of IPC4 testench is similar as with IPC3.